I think it’s important to distinguish between “fitness as evaluated on the training distribution” (i.e. the set of environments ancestral peacocks roamed) and “fitness as evaluated on a hypothetical deployment distribution” (i.e. the set of possible predation and resource scarcity environments peacocks might suddenly face). Also important is the concept of “path-dependent search” when fitness is a convex function on X which biases local search towards X=1, but has global minimum at X=−1.
In this case, I’m imagining that Fisherian runaway boosts X as long as it still indicates good fitness on-distribution. However, it could be that X=1 is the “local optimum for fitness” and in reality X=−1 is the global optimum for fitness. In this case, the search process has chosen an intiial X-direction that biases sexual selection towards X=1. This is equivalent to gradient descent finding a local minima.
I think I agree with your thoughts here. I do wonder if sexual selection in humans has reached a point where we are deliberately immune to natural selection pressure due to such a distributional shift and acquired capabilities.
I think it’s important to distinguish between “fitness as evaluated on the training distribution” (i.e. the set of environments ancestral peacocks roamed) and “fitness as evaluated on a hypothetical deployment distribution” (i.e. the set of possible predation and resource scarcity environments peacocks might suddenly face). Also important is the concept of “path-dependent search” when fitness is a convex function on X which biases local search towards X=1, but has global minimum at X=−1.
In this case, I’m imagining that Fisherian runaway boosts X as long as it still indicates good fitness on-distribution. However, it could be that X=1 is the “local optimum for fitness” and in reality X=−1 is the global optimum for fitness. In this case, the search process has chosen an intiial X-direction that biases sexual selection towards X=1. This is equivalent to gradient descent finding a local minima.
I think I agree with your thoughts here. I do wonder if sexual selection in humans has reached a point where we are deliberately immune to natural selection pressure due to such a distributional shift and acquired capabilities.